Tailored highly efficient Co-doped TiO2/CoTiO3 heterojunction photocatalyst for methylene blue degradation under visible light |
Rajmoni Basumatary1, Bablu Basumatary2, Dimpul Konwar3, Anjalu Ramchiary1 |
1Nano Energy Materials Laboratory, Department of Physics, Bodoland University, Kokrajhar, Assam 783370, India 2Institute of Advanced Study in Science and Technology, Guwahati, Assam 781035, India 3Department of Materials Science and Engineering, Gachon University, Bokjung-dong, Seongnam-si , Gyeonggi-do 1342, Republic of Korea |
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Received: November 9, 2022; Revised: December 20, 2022 Accepted: December 22, 2022. Published online: January 9, 2023. |
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ABSTRACT |
A typical Co-doped TiO2/CoTiO3 heterostructure photocatalyst was synthesized using a facile and cost-effective modified sol–gel route. The as-prepared photocatalysts were further annealed at 400, 600, and 700 °C temperatures and termed CT400, CT600, and CT700, respectively. The XRD analysis of the CT600 photocatalyst reveals the presence of anatase–rutile homojunction and the high crystallinity nature of TiO2. The spectral response and the bandgap of the photocatalysts were analyzed using UV-DRS. The decrease in bandgap due to Co ion doping as well as the synergistic eff ect of both homojunction and heterojunction in Co-TiO2/CoTiO3 significantly enhanced the photocatalytic activity under visible light. The presence of oxygen vacancies, charge carrier migration, and the chemical compositions of the photocatalysts were studied using ESR, PL, and XPS techniques. Under the visible light, Co-TiO2/CoTiO3 (CT600) photocatalyst exhibited 97% degradation of methylene blue in 90 min, which is ~ 42-fold higher than that of pristine TiO2. No sacrificial reagents were applied in this research. Notably, this visible light active Co-TiO2/CoTiO3 photocatalyst has the potential for the application of large-scale solar-induced dye removal. |
Key words:
Photocatalysis · Heterojunction homojunction · Methylene blue · Visible light |
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